Pellet-inserting machine for piano-keys



S. SYLVESTER. PELLET INSERTING MACHINE FOR PIANO KEYS. I APPLICATION FILED OCT. 26, 1920. 1,383,497. Patented July 5,1921

63 4 SHEETS-SHEET I. W

A; Atty S. SYLVESTER. PELLET INSERTING MACHINE FOR PIANO KEYS.

' APPLICATION FILED OCT- 26, 1920. 1,383,497.

Patented July 5, 1921 4 SHEETS-SHEET 2.

4 Atty S. SYLVESTER. PELLET INSERTING MACHINE FOR P-IANO KEYS. APPLICATION FILED OCT. 26. 1920.

1,383,497. Patented July 5, 1921.

4 SHEETS-SHEET 3.

In Ven tor: fikymour \g/z/asfi r.

by ga %4 Atty S. SYLVESTER. PELLET INSERTING MACHINE FOR PIANO KEYS. APPLICATION men OCT- 26. 1920.

1,383,497. Patented July 5,1921

%i I 4 SHEETS-SHEET 4- est: Inventor:

I \fgwwwg fl asf r Atty UNITED STATES PATENT OFFICE.

SEYMOUR sYLvEs'rEn, or BROOKLYN, new YORK, ASSIGNOB TO BASS BROS. moon PORATED, or new YORK, 1v. Y.

PELLET-INS E-RTING MACHINE FOR PIANO-KEYS.

Specification of Letters Patent.

Patented July 5, 1921.

Application filed October 26, 1920. Serial No. 419,625.

To all whom itmay concern:

Be it known that I, SEYMOUR SYLvns'rnR, a citizen of the United States, residin at Brooklyn, in the county of Kings and tate of New York, have invented certain new and'useful Improvements in Pellet-Inserting Machines for Piano-Keys, of which the following is a specification.

My invention relates to an improved machine for inserting weights in piano keys for the purpose of balancing the latter.

In the manufacture of piano keys it is essential that the key be weighted in order that it may exactly balance so as to be highly sensitive and responsive to the touch of the player. The weight is usually inserted at one side of the center of the balance point of the key. The precise position of the weight is a matter of extreme importance, and to determine where the weight is to be inserted the prevailing practice is to place the key on a balancing device of some sort and by manipulation ascertain the pro cise point atwhich the keybalances. Thereupon a mark is made in the key to indicate the place where the weight is to be inserted. These operations are time consuming and laborious, and require the work of the highest skilled operators. Even with the greatest of care it frequently happens that the indicating mark for the weight is not accurately placed and consequently the weight itself is inserted at a point which might be very slightly removed from the proper place of insertion, and consequently the key is off balance.

The cost of accurately balancing the piano keys by weighting the latter is a very large factor in determining the cost of the completed piano.

lVith the foregoing in mind I have devised a machine, which I believe to be broadly new, by which the correct balance of a piano key may be found with absolute accuracy and by mechanical means. and after the balance has been found the weight pellet inserted in precisely the right place to obtain the desired result. These several operations are so correlated that in addition to obtaining absolute accuracy, very considerable speed of operation is secured, thus not only enabling me to produce a more satis- ..;factory key than heretofore, but to do this to that illustrated in Fig. 1.

at a very greatly reduced cost, thereby permitting reduction in the cost of the piano itself.

Stated broadly the invention comprises balancing mechanism for a piano key combined with means for inserting a weight in the key at the proper position determined by the balancing means.

Comprehended in my invention are various details of structure which contribute to obtaining the results aimed at, and the invention will be best understood by refer ence to the accompanying drawing, wherein Figure 1 is a plan view of my invention showing the several parts in their neutral or lnoperative position.

Fig. 2 is a front elevational view of the device with the parts in a similar position Fig. 3 is a substantially vertical sectional view taken on the lines 33 of Fig. 1.

Fig. 4: is a substantially transverse sectional view taken on the lines 4:-.L of Fig. 2.

Fig. 5 is a sectional view of the balancing mechanism and adjacent parts taken on the lines 55 of Fig. 1.

Fig. 6 is a perspective view of the key balance showing the adjustable centering pin mounted therein.

Fig. 7 is a perspective view of a piano key showing a pellet inserted therein and ready to be installed in a piano key board.

Fig. 8 is a detail perspective view of the holding jaws and their guides. V

Fig. 9 is a perspective view of a portion of the clamping rod showing the eccentrically cut portions adapted to initiate the clamping movement of the jaws.

Fig. 10 is a substantially'vertical sectional view of a slightly modified form of constructing the key balance and its relative position beneath the action of a piano.

Fig. 11 is a perspective view of the modified form of key balance shown in Fig. 10.

Referring to the drawing, 10 denotes the platform or base upon which'the balancing, drilling and pellet inserting mechani'sm is mounted. A raised portion 11 extending transversely of the base 10 is provided with parallel marginal guides 12. Guide plateslS overlie the guides 12 and are attached thereto by means of screws 14 extending into the body of the raised portion the clamping'plates 19 which are secured thereto by means of screws 20. The clamping jaws 17 are provided on their underside with slide blocks 21 guided in the guideways 13, above referred to. Projecting below the clamping jaws 17 and forming a part thereof are lugs 22 movable in suitable openings 23 in the carriage 15, saidlugs 22 being acted upon by springs 24, which tend to hold the aws apart as shown in Fig. 3. The slide blocks 21 are held from vertical displacement by a bar 25 countersunk into the upper surface of the carriage 15, and said bar 25 overlies the central portion of the slide blocks 21 and is secured to the carriage at its ends by screws 26. A revoluble shaft 27 is mounted axially of the carriage 15 and is provided with eccentrically cut portions 28 adapted to intersect the openings 23 and engage the depending lugs 22 as shown in Fig. 9. A suitable angular bent portion 29' located outside the carriage 15 provides a grip'whereby the shaft may be revolved to cause the jaws 17 to advance and recede.

The platform or base 10 is provided with a longitudinally disposed groove or slot 30 extending substantially the entire lengthof the base and adapted to receive therein. a slide-member 31 having a drill standard 32 and ram standard 33 at opposite ends.

Movement is imparted to the slide member by a lever 34 pivoted to the ram standard 33 and having a'forked end 35 adapt-ed'to engage under the head of a fulcrum pin 36. In order that the movement of the slide 31 toward the left may be limited, as shown by the dotted line A of Fig. 1, a set screw 37 is provided in a plate 38 secured to the edge of the base 10 spanning the groove 30.

Secured to the guide plates 13 and lo cated equi-distantly from the intersecting point of the groove 30 with the axis of carriage 15 are four posts 39, arranged in pairs at eachside of the groove 30, connected at their upper ends by plates 40 and support.

ing a bridge plate 41. Said bridge plate 41 has mounted therein a collar 42 which is in axial alinement with the aforenoted intersecting polnt. A slidable. trial weight 43 is mounted in the vertical bore of the collar 42 which is provided with an enlarged. portion at its upper end for the reception of the head of the trial weight 43. Midway between the posts 39 and mounted upon'the left guide plate 13 is a hopper 44 "through the opening 46 in'the hopper 44 and. into the space between the clamping plates 19 and the clamping jaws 17, as shown in Fig. 3. Moving with the ram 47 is a drill 48 mounted in a chuck 49 rotatably supported in the drill standard 32.

The ram 47 and drill 48 are in axial alinement, as they are designed to operate on the same plane. The opposite end of the chuck 49 is provided with a keyway 50 for the reception of the key of a coupling member 51 fixed to the motor shaft 52 of a motor.

53. By reasonof this construction the retary motion ofthe motorshaft 52 may be imparted to thereciprocating chuck '49 and drill 48. The movement of the slide 31 is confined to the groove 30 by a plate 53 secured to the base 10 at either side of the slide 31. s 1

- Balance posts 54 carried by the carriage 15 extend upwardly adj acent the inner faces of the jaws 17 to a'point above the clamping plates 19 and are provided with bifurcated ends v55 to support a key balance member 56 having upwardly disposed hangers 57 provided with oppositely extending pins 58 adapted torest in the forked ends 55 of the posts 54. The key balance member 56 disposed-axially of the carriage 15 is free to rock between the inner faces of the jaws 17. In order that the movement of the clamping plates 19 may not be interfered with, the latter are recessed at 59 toaccommodate the stationary balance posts 54. The'forward end of the key balance 56 car rie's vertically extending spring fingers 60, to hold the key Bin axial alinement with the balance member 56. A longitudinal slot 61 .in the body of the balance member 56, shown in Fig. 5, accommodates a slidably mounted balance pin 62. A screw 63 hdV'.

that the key Bmay be perfectly balanced, V

the latter must be moved theproper extent transversely ofthe axis of the drill 48and ram 47, as hereinafter described, andthis is accomplished by moving the carriage 15;

upon which the key balance is supported, by'means of apinion 65 engaging a rack 66 carried at the under side of the carriage 15. The pinion 65 revolves with a shaft 67 suitably mount-ed in'bearings 68 on the platform 10. Said shaft 67 is provided with a knurled hand wheel 69.

for the reception of pellets or weights 45. Referring to themodified form'shown in Fig. 10, the rear end of the balance member 56 is provided with an extension rod 70 which is adapted to extend into the case of a piano C (shown only in dotted lines) and receives the weight of the action D upon the upturned end 71 of the rod 70. This construction makes possible not only the correct balance of the key as such, but the weight of the action is also taken into account. In order that different lengths of keys may be balanced by the same mechanism, I provide a scale having the letters B for bass, vM for medium and T for treble indicated on the'side of the member, so that by moving the screw 63, the balance pin 62 may be set at either of the letters to take care of any of the several lengths of keys.

In the operation of the device the key to bebalanced is placed between the spring fingers 60 of the key balance 56 and moved axially until the balance pin 62 enters the hole provided in the under side of the key B. The position of the balance pin .62 in the slot 61 will depend upon whether the key is designed to be a bass, medium or treble key. This is, simply, taken care of by turning the screw 63 until the balance pin 62 travels to the desired mark, B, M, or T. An intermediate scale isprovided on the upper face of the balance member 56 so that any makeor length of key may be accommodated. When the key B is in proper position the trial weight 43 rests upon the upper surface of the rear portion of the key. The carriage 15 is moved by turning the knurled hand wheel 69, and pinion 65 until the trial weight 43 counterbalances the forward portion of the key B, whereupon the handle 29 is rotated and the jaws 17 and clamping plates 19 advance toward each other, engaging the sides of the balancing key where the latter is then rigidly held in horizontal position and prevented from further rocking movement. 7

The next step in the operation of the device involves the drilling of. a hole in the body of the key at a point directlyin line with the axis of the trial weight 43. step is accomplished by moving the hand lever 34 to the left, as shown at A, and advancing. the drill standard 32 and drill 48 toward the key B. The movement is continued until the ram standard 33 abuts the screw 37, which limits its travel and prevents the drill 48 from advancing too far through the key. The. ram 47 moving with the drill recedes a sufficient distance to clear the opening 46 in the hopper 44 and a pellet 45 is permitted to drop in front of the ram 47.

The final step of the operation is the in'- sertion of the pellet into the drill hole made by the drill 48. The handle 34 should be rapidly moved to the right advancing the rain 47 and pellet 45 toward the key B. As

he resi s t e d ll w l we at 22, tending to separate the latter.

This.

the pellet will be forced into'the drill hole. The pellet 45 should be slightly larger than the size of the drill 48 in order that the pellet may be driven into the hole to insure permanent setting of the pellet. The handle 29 is again moved to release the jaws 17 whereupon the key may be removed, perfectly balanced, and ready to be inserted in its place on the key board of the piano.

.The advance and recession of the clamping jaws 17 are initiated by the action of the eccentric portions 28 of the shaft 27, as shown in Fig. 9, engaging the lugs 22. To

advance the jaws to clamping position the shaft 27 is rotated toward the right bringing the full side of the shaft against the lugs This movement will move the jaws toward each other. To release the'jaws the opposite rotation of the shaft 27 will advance the eccentric side of the latter to the lugs 22 which will be forced apart by their respective springs 24.

The operation of the modified form of the invention, shown in Figs. 10 and 11, is the same as that of the preferred form with the exception that the entire device must be so supported that it may be capable of being .inserted into the body of the piano, theextension receiving the weight of the action D. VJhatever form or shape of pellet may be used to balance the keys, it will be understood that they must equal in weight the trial weight 43.

The foregoing description presupposes a condition in which hole is drilled or otherwise made in the piano key prior to the insertion of the pellet in position. It is, however, within the purview of my invention to force or insert the pellets into the key in the proper position. without previously forming an opening in the key for the reception of the pellet. In a case of this kind the pellet would preferably be pointed and might be of steel or other suitable material to hold the point, and the pellet would be driven into 7 position by the action of the ram 47. It has. not been deemed necessary to illustrate this arrangement, as the only change required in the machine is the dismounting. of the drill 48.

Referring to Fig. 3 the ram 47 is provided at its free end with a cone shaped projection 47 The function of the projection 47 is to expand the pellet 45 after the latter has been driven into the opening in the key B. This is accomplished by forcing the'projection 4'? into the face of the pellet 45 thereby displacing the metal of the pellet regularlyagainst the inner periphery of the opening in the key.

I claim 1. In mechanism of the character described, a piano key balance member, means for determining the position in which to said balance member, and means carried by the slide for making a weight receiving opening in said key.

5. In mechanism of the character described, a balance member for the reception of a piano key, a slide. movable transversely to said balance member, means carried by said slide for making a weight receiving opening in said key, and weight inserting means carried by said slide.

6. In mechanism of the character described, a balance member for the reception of a piano key, a slide movable transversely to said balance member, and a drill and a ram carried by said slide, and means to move saidbalance member across the path of said slide.

7. In mechanism of the character described, a balance member for the reception of a piano key, a carriage upon which said balance member is mounted, a slide movable across the path of said carriage, a drill and a ram mounted on said slide, and means whereby said carriage may be moved to a predetermined point in relation to the drill and ram.

8. In mechanism of the character described, a platform having a piano key balancing and pelletinsertin mechanism movably mounted thereon, and means supported by said platform and cooperating with said balancing mechanism for predetermining the field'of operation of the pellet inserting mechanism.

' 9. In mechanism of the character de scribed, a carriage member having a key balance for the reception of a piano key, a slide having a drill and a ram transversely movable across the path of said carriage, and a trial weight loosely supported above said key at the intersecting point of the slide with the axis of the carriage.

.10. In a-mechanism of the character described, a carriage having a key balancing member mounted thereon, said balancing member provided with means for retaining a piano key therein, a transversely movable slide having a drill and a ram adapted to act on said key, and means whereby weights may be fedin the path of said 11. In mechanism of the character de-: scribed, a carriage hav ing akey balancing, member for the reception ofa piano key, means for clamping said piano key in afixed position, a slide movable transversely to said carriage, means carried by. said slide. for making a weight receiving opening in said key, and means also carried by said slide for inserting a weight in said opening.

12. In mechanism of the character described, a carriage having a key balancing member for the reception of a piano key, clamping jaws movable in said carriage and arranged on opposite sides of said balancing member, means for moving said clamping jaws, a slide movable transversely to said carriage, and adrill and a ram for acting on said piano key.

13. In mechanism of the character de- V scribed, a carriage comprising a balancing member for the reception of a piano key, a movable balance pin mounted in said balance member, clamping means associated with said carriage and adjacent said balance member whereby said key may be rigidly held in a fixed position, weightv inserting means movable transversely of said carriage, and means for moving the latter across the path of said weight inserting means.

14. In mechanism of the character described, a platform having a slide and a carriage movably supported thereby, means for reciprocating said slide, means. for reciprocating said carriage,- means for guiding the latter across the path of travel of said slide, and a trial weight above the axis of said slide at the intersecting point of the latter with the axis of the carriage.

15. In mechanism of the character de- I scribed, a key balance membercomprising a barfor the receptionof a piano key and provided with an adjustable balance pin, clamping. jaws adjacent the sides of said balance member, a movable carriage supporting said key balance and clamping jaws, an eccentric'control rod cooperating with said clamping jaws whereby the latter may be moved transversely to said balance member, a slide movable transversely of said carriage, said slide provided withmeans for makingan opening insaid key and located at oneside of said carriage and a weight inserting means disposed at the opposite side of said carriage, and 'mcans'whereby said slide may. be reciprocated.

16. In mechanism of; the character described, a piano keybalancemember for the reception of a piano key, an adjustable balance pin in said memberjand capable of movement relative to the keybalance, a carriagev for supporting said balance member, means for moving said carriage, a slide movable transversely of said carriage, a drill and a ram mounted on said slide and a trial We ght depending above said c r i ge an said slide, said trial weight adapted to rest upon said piano key to determine the balance point.

17 In mechanism of the character described, key balancing means, for the reception of a piano key, a movable carriage supporting said key balancing means, a slide transversely movable of said carriage, clamping jaws closely adjacent said key balance, means for operating said jaws, means carried by said slide for making a weight receiving opening in said key, means carried by said slide for inserting a weight in said opening,

' said last named means arranged on the opposite side of said carriage tosaid means for making the opening in the key, a lever piv oted to said slide for imparting movement to the latter, a hopper fior the reception of said weights and an opening in said hopper whereby said weights may be fed in advance of said. inserting mechanism, and a trial weight depending above the axis of said slide at a point where the axis of the carriage intersects the axis of said slide.

18. In mechanism of the character described, a key balancing member for the reception of a piano key, a balance pin carried by said balance member and movable relative to the latter, a slide reciprocable transversely of said balance member, a drill carried by said slide,a motor for imparting rotary motion to the drill, a union intermediate said drill and said motor whereby the former may be reciprocated during its rotary movement, a ram carried by said slide at the opposite side of said balancing member, a lever for reciprocating said slide, and an adjustable stop for limiting the movement of said slide.

19. In mechanism of the character described, a piano key balance member, means for inserting a weight in said piano key, and means whereby the weight of a piano action may be exerted upon said balance member.

20. In mechanism of the character described, a piano key balance member, an extension carried by said member provided to receive the weight of a piano action and including said weight in the balance of said key, a slide movable transversely to said balance member, means carried by said slide for inserting a Weight in said piano key,-and a trial weight bearing upon said key.

21. In mechanism of the character described, a piano key balance member having a movable balance pin, means for moving said balance pin, and a scale on said member whereby said balance pin may be set at a predetermined point in said balance member to accommodate different lengths of piano keys.

In testimony whereof I have affixed my signature.

SEYMOUR SYLVESTER. 

